/*------------------------------------------------------------------------
 *  SymbolIterator
 *
 *  Copyright 2007-2010 (c) Jeff Brown <spadix@users.sourceforge.net>
 *
 *  This file is part of the ZBar Bar Code Reader.
 *
 *  The ZBar Bar Code Reader is free software; you can redistribute it
 *  and/or modify it under the terms of the GNU Lesser Public License as
 *  published by the Free Software Foundation; either version 2.1 of
 *  the License, or (at your option) any later version.
 *
 *  The ZBar Bar Code Reader is distributed in the hope that it will be
 *  useful, but WITHOUT ANY WARRANTY; without even the implied warranty
 *  of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser Public License
 *  along with the ZBar Bar Code Reader; if not, write to the Free
 *  Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 *  Boston, MA  02110-1301  USA
 *
 *  http://sourceforge.net/projects/zbar
 *------------------------------------------------------------------------*/

package net.sourceforge.zbar;

/**
 * Iterator over a SymbolSet.
 */
public class SymbolIterator
        implements java.util.Iterator<Symbol> {
    /**
     * Next symbol to be returned by the iterator.
     */
    private Symbol current;

    /**
     * SymbolIterators are only created by internal interface methods.
     */
    SymbolIterator(Symbol first) {
        current = first;
    }

    /**
     * Returns true if the iteration has more elements.
     */
    public boolean hasNext() {
        return (current != null);
    }

    /**
     * Retrieves the next element in the iteration.
     */
    public Symbol next() {
        if (current == null)
            throw (new java.util.NoSuchElementException
                    ("access past end of SymbolIterator"));

        Symbol result = current;
        long sym = current.next();
        if (sym != 0)
            current = new Symbol(sym);
        else
            current = null;
        return (result);
    }

    /**
     * Raises UnsupportedOperationException.
     */
    public void remove() {
        throw (new UnsupportedOperationException
                ("SymbolIterator is immutable"));
    }
}
